This invention relates to a ceramic-polymer composite material, and, more particularly, to its use in making a microelectronics package.
A common approach to the fabrication of electronic devices is to form the electronic circuitry as a thick film having a large number of superimposed layers and interconnect circuitry, in a microelectronic package. The materials are selected to have required electronic, thermal, and mechanical properties, and the circuits are patterned to define the geometries of the circuit elements. With this approach, compact, light, fast devices may be made with large numbers of circuit elements in a single package. The circuits on the packages are connected externally with electrically conductive paths such as traces or vias.
The active chips are mounted on the package so as to be accessible and easily handled. The package is typically a ceramic housing having a generally flat base and a lid. The chip is mounted to the package base, external connections are made, and the lid is sealed over the base and its mounted chip. The package may be designed to be only physically protective, or it may also be made hermetic to protect against environmental attack.
In some packaging applications, the electronics inside the package produces a substantial amount of heat which heats the package. The entire package may also be heated and/or cooled during service by the external environment. The package must be effective to conduct heat away from the chip. Additionally, the package must not induce such large thermal strains in the chip that the chip is distorted or permanently damaged during service.
Electronics packages are typically made of sintered ceramics, metals, or alloys. A variety of designs and materials are employed in order to meet the technical requirements, and the packages also must be producible at an acceptable cost. There remains, however, a need for improved microelectronic packaging.